In recent years, there has been significant research and development in the biomedical field with regard to drug delivery devices and, in particular, implantable bio-compatible microchip drug delivery devices. In general, an implantable microchip drug delivery device includes an array of micro-scale reservoirs that are formed in a substrate. The reservoirs are filled with certain medications/drugs that are contained within the reservoirs using releasable membrane structures. The microchip drug delivery devices are designed with various types of actuation mechanisms that allow the contents of the reservoirs to be automatically released (via the releasable membrane structures) either continuously, periodically or “on demand” by an individual (e.g., doctor or patient). These actuation mechanisms generally include passive and active release mechanisms.
By way of example, with passive release mechanisms, porous releasable membrane structures can be utilized which allow the contents of the reservoirs to slowly diffuse out from the reservoirs. Alternatively, a passive release mechanism can be configured to deteriorate over time to release the reservoir contents. Furthermore, an example of an active release mechanism includes releasable membranes that are configured to rupture using electrical actuation mechanisms. In general, these active release mechanisms utilize a power source, such as a thin-film battery, to provide an electrical current and/or voltage that is sufficient to rupture or otherwise melt or vaporize a membrane structure to thereby provide controlled release of reservoir contents. When drug delivery over a long period of time is required, it is necessary to minimize the energy requirements for active release mechanisms to ensure proper device operation, as well as minimize any adverse impact of the power dissipation on the reservoir contents to be released as well as organism cell function. Although a variety of active reservoir release methods have been proposed, none of the proposed methods implement low-power release mechanisms for rupturing releasable structures.